<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    <script src="js/bootstrap.min.js"></script>
</head>
<body>
<!-- Single button -->
<div class="btn-group">
    <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Action <span class="caret"></span>
    </button>
    <ul class="dropdown-menu">
        <li><a href="#">Action</a></li>
        <li><a href="#">Another action</a></li>
        <li><a href="#">Something else here</a></li>
        <li role="separator" class="divider"></li>
        <li><a href="#">Separated link</a></li>
    </ul>
</div>
<!-- Split button -->
<div class="btn-group">
    <button type="button" class="btn btn-danger">Action</button>
    <button type="button" class="btn btn-danger dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        <span class="caret"></span>
        <span class="sr-only">Toggle Dropdown</span>
    </button>
    <ul class="dropdown-menu">
        <li><a href="#">Action</a></li>
        <li><a href="#">Another action</a></li>
        <li><a href="#">Something else here</a></li>
        <li role="separator" class="divider"></li>
        <li><a href="#">Separated link</a></li>
    </ul>
</div>
</body>
</html>